Abstract

1. The toxicity (L.D. 50) by intraperitoneal injection in white mice of diethylaminoethyl ester of diphenyl acetic acid ("Trasentin") is 0.29 gram per kilogram; that of diethylaminoethyl ester of phenylcyclohexyl acetic acid ("Trasentin-6H") is 0.24 gram per kilogram; that of atropine sulphate is 0.325 gram per kilogram.

2. "Trasentin" is a convulsant and respiratory stimulant in sub-lethal doses; "Trasentin-6H" is a respiratory stimulant in small doses, but in lethal doses depresses respiration.

3. "Trasentin" inhibits the normal tone and movements of the isolated intestine of the rabbit in concentrations of 1:1,000,000, and relaxes spasm caused by barium chloride and eserine salicylate. "Trasentin-6H" exerts the same effects in doses of 1:5,000,000 and is a more powerful spasmolytic.

4. In the intact rabbit anesthetized with ether, and in the spinal cat, the tone and movements of the intestine are inhibited by 0.01 to 0.02 mgm. per kilogram "Trasentin-6H" and 0.1 mgm. per kilogram "Trasentin." The stomach and bladder of the cat are relaxed by 0.05 mgm. per kilogram "Trasentin-6H."

5. "Trasentin-6H" in doses which are effective on the tone of the gastrointestinal tract has very little effect on salivation produced by pilocarpine nitrate, on heart rate or action, on the size of the pupil, on respiration or on the parasympathetic nerve supply to the cardio-vascular system, as compared with atropine sulphate.

6. "Trasentin-6H" is about 25 per cent more toxic than atropine sulphate but has a proportionately greater spasmolytic action. In antagonising the action of muscular stimulants like barium it is almost as potent as papaverine. As it is relatively free from "side-effects" it seems worthy of clinical trial.